1. Field of the Invention
Exemplary aspects of the present invention generally relate to an image forming apparatus, and more particularly to an image forming apparatus including a recording head that ejects liquid droplets.
2. Description of the Related Art
One example of related-art image forming apparatuses such as printers, copiers, plotters, facsimile machines, and multifunction devices having two or more of printing, copying, plotting, and facsimile capabilities is an inkjet recording device employing a liquid ejection recording method. The inkjet recording device includes a recording head that ejects droplets of a recording liquid such as ink from nozzles in the recording head onto a sheet of recording media while the sheet is conveyed to form an image on the sheet. Examples of an inkjet recording device include a serial-type image forming apparatus, in which the recording head ejects ink droplets while moving in a main scanning direction to form an image on the sheet as the sheet is moved in a sub-scanning direction perpendicular to the main scanning direction, and a line-type image forming apparatus equipped with a line-type recording head that ejects ink droplets and does so without moving to form an image on the sheet as the sheet is moved in the sub-scanning direction.
The inkjet recording device further includes a servicing mechanism to maintain stable ejection of ink droplets from the nozzles in the recording head (i.e., to keep the nozzles clean). The servicing mechanism includes a cap that caps a nozzle face of the recording head (i.e., the face of the recording head in which the nozzles are disposed) to prevent ink within the nozzles from getting dried out and clogging the nozzles and dust and foreign substances from entering the nozzles, a wiper that wipes off the nozzle face of the recording head to clean the nozzle face, and so forth. After viscous ink is discharged from the nozzles into the cap that covers the nozzle face, the wiper wipes off the nozzle face to form a meniscus at the nozzles, thereby servicing the recording head.
There is known a servicing mechanism including a suction cap movable in a horizontal direction to cover the nozzle face of the recording head disposed in a vertical direction. The suction cap includes an escape opening provided at an upper portion thereof and a suction opening provided at a lower portion thereof.
In order to prevent leakage of ink from the suction cap during suction of ink from the nozzles in the recording head, first, the nozzle face is capped with the suction cap, next, ink is sucked out from the nozzles to the suction cap, then, a space enclosed within the suction cap is opened to the atmosphere so that the ink is discharged from the suction cap via the suction opening, and finally, the suction cap is removed from the nozzle face of the recording head.
However, because a slight amount of ink sucked out from the nozzles to the suction cap remains within the suction cap even after discharge of the ink from the suction cap, the ink may drop from the suction cap upon removal of the suction cap from the nozzle face of the recording head, resulting in adhesion of the ink to a cap holder. In addition, the ink adhering to the suction cap may prevent the suction cap from properly covering the nozzle face and forming the enclosed space between the nozzle face and the suction cap. Consequently, the nozzles may get dried out and clogged with viscous ink, resulting in deterioration of the suction performance for servicing the nozzles.